Gov. Jerry Brown, who is seeking legislative approval this summer to start construction on the $68 billion project, angered environmentalists when his administration proposed this month to limit the circumstances in which a court could block construction of the project under the landmark California Environmental Quality Act.

Kathryn Phillips, director of Sierra Club California, said a Brown adviser sent environmentalists and transportation advocates an e-mail today indicating the Democratic governor was backing off.

Phillips said the administration suggested it could revisit the proposal later.

"They're not interested for now," Phillips said. "So I feel like I can sleep well tonight, and there will be another day when we will have to struggle with how we can ensure that we protect environmental quality."